guidata not updating in MATLAB GUI

Question

I have a MATLAB GUI with:
1) A VLC window controlled by activex.
2) A bunch of radiobuttons to "annotate" the video on particular frames.

I have working code, but I'm missing the output from the function that is called for annotation. This function, Annotate, should substitute the annotated values into a previously created table final_data. I can display the substituted values to console, I would expect guidata to update handles, so the output of my main function should contain a .final_data field with the updated values. However, calling .final_data on the output object returns the empty placeholder values.

function Annotate(varargin)

    hFigure = findobj('tag', 'VideoPlay');
    handles = guidata(hFigure);

    % change value of the orther button to 0
    set(handles.hNotAnnotateButton, 'Value', 0);

    mypos = handles.vlc.input.Position; % >> proxy to calculate frame
    behavior = handles.Behavior;  % >>> Tag to be annotated

    % Calculate frame
    myframe = ceil(handles.vlc.input.Time/1000 * handles.frameRate) - 1;

    handles.final_data.behavior(myframe) = behavior;

    display(handles.final_data(myframe, :)) % displays properly

    guidata(handles.hFigure, handles) % not updating handles??
end

Just in case, here's the full function

function handles = AnnotateVideo(filepath) 

    % Get some initial data from the video
    filepath = fullfile(filepath);

    % Get file duration

    v = VideoReader(filepath);
    handles.duration = v.Duration;
    handles.frameRate = v.FrameRate;
    delete(v)

    total_frames = ceil(handles.duration * handles.frameRate) - 1;


    %% Make some variables

     handles.final_data.frameID = (1:total_frames)';
     handles.final_data.behavior = strings(total_frames, 1);

     % change format to table
     handles.final_data = struct2table(handles.final_data);

    % Place Holder for behavior


    %% Build the Figure/GUI

    % Video will be kept on handle
    handles.filepath = filepath; 
    % Create figure to receive activex 
    handles.hFigure = figure('position', [50 50 1300 560], ...
                             'menubar', 'none', 'numbertitle', 'off', ...
                             'name', ['Video: ' filepath],...
                             'tag', 'VideoPlay', 'resize', 'on'); 

    % Create play/pause and seek to 0 button 
    handles.hTogglePlayButton = uicontrol(handles.hFigure, ...
                                          'position', [0 540 80 21], ...
                                          'string', 'play/pause', 'callback',...
                                          @TogglePlayPause); 
    handles.hSeekToZeroButton = uicontrol(handles.hFigure, ...
                                          'position', [81 540 80 21], ...
                                          'string', 'begining', 'callback',...
                                          @SeekToZero); 

    handles.hGoToStartFrameButton = uicontrol(handles.hFigure, ...
                                          'position', [161 540 80 21], ...
                                          'string', 'StartFrame', 'callback',...
                                          @SeekToStartFrame);   

    handles.hGoToEndFrameButton = uicontrol(handles.hFigure, ...
                                          'position', [241 540 80 21], ...
                                          'string', 'EndFrame', 'callback',...
                                          @SeekToEndFrame);                                        

%% Annotate button

    handles.hAnnotateButton = uicontrol(handles.hFigure, ...
                                          'Style', 'radiobutton', ...
                                          'position', [980 320 100 41], ...
                                          'String', 'Annotate', 'callback',...
                                          @Annotate);
   handles.hNotAnnotateButton = uicontrol(handles.hFigure, ...
                                       'Style', 'radiobutton', ...
                                       'position', [1100 320 100 41], ...
                                       'String', 'Not-Annotate', ...
                                       'Value', 1, ...
                                       'callback', @NotAnnotate);



%% Make radio buttons for ethogram

handles.radio(1) = uicontrol('Style', 'radiobutton', ...
                           'Callback', @myRadio, ...
                           'Units',    'pixels', ...
                           'Position', [980, 500, 80, 22], ...
                           'String',   'Non-specific', ...
                           'Value',    0);
handles.radio(2) = uicontrol('Style', 'radiobutton', ...
                           'Callback', @myRadio, ...
                           'Units',    'pixels', ...
                           'Position', [980, 480, 80, 22], ...
                           'String',   'Rearing', ...
                           'Value',    0);

handles.radio(3) = uicontrol('Style', 'radiobutton', ...
                           'Callback', @myRadio, ...
                           'Units',    'pixels', ...
                           'Position', [980, 460, 80, 22], ...
                           'String',   'Snif', ...
                           'Value',    0);

handles.radio(4) = uicontrol('Style', 'radiobutton', ...
                           'Callback', @myRadio, ...
                           'Units',    'pixels', ...
                           'Position', [980, 440, 80, 22], ...
                           'String',   'Retrieving', ...
                           'Value',    0);                       

handles.radio(5) = uicontrol('Style', 'radiobutton', ...
                           'Callback', @myRadio, ...
                           'Units',    'pixels', ...
                           'Position', [1100, 500, 80, 22], ...
                           'String',   'Self-Groom', ...
                           'Value',    0); 


%% Activex control for VLC player

    % Create activex control 
    handles.vlc = actxcontrol('VideoLAN.VLCPlugin.2', [0 0 960 540], handles.hFigure); 
    % Format filepath so that VLC can use it


    % Read into vlc

    filepath = ['file://localhost/' filepath]; 


    % Add file to playlist 
    handles.vlc.playlist.add(filepath); 

    % Play file 
    handles.vlc.playlist.play(); 
    % Deinterlace 
    handles.vlc.video.deinterlace.enable('x'); 
    % Go back to begining of file 
    handles.vlc.input.time = 0; 


   % Register an event to trigger when video is being played regularly 
   handles.vlc.registerevent({'MediaPlayerTimeChanged', @MediaPlayerTimeChanged}); 

   % Position changed
   handles.vlc.registerevent({'MediaPlayerPositionChanged', @MediaPlayerPositionChanged});

   % Save handles 
   guidata(handles.hFigure, handles); 


%% Helper functions and button callbacks    


   function MediaPlayerPositionChanged(varargin)
   hFigure = findobj('tag', 'VideoPlay');
   handles = guidata(hFigure);

   % Get position
   handles.mypos = handles.vlc.input.Position;

   % Get frame
   handles.myframe = handles.vlc.input.Time;

   % If position is changing AND annotate button is 'ON' (value == 1)
   % Annotate
   will_annotate = get(handles.hAnnotateButton, 'Value');

   if(will_annotate)
   Annotate
   end

   end

%% Display running time in application title 

    function MediaPlayerTimeChanged(varargin) 
   hFigure = findobj('tag', 'VideoPlay'); 
   handles = guidata(hFigure); 

   myframe = handles.vlc.input.Time;

   set(hFigure, 'name', [handles.filepath ' ; ' num2str(myframe/1000) ' sec.']);

    end

%% Annotate: MAIN 'Looping' Function
% called when position is changed and annotate button

        function Annotate(varargin)

            hFigure = findobj('tag', 'VideoPlay');
            handles = guidata(hFigure);

            % change value of the orther button to 0
            set(handles.hNotAnnotateButton, 'Value', 0);

            mypos = handles.vlc.input.Position;
            behavior = handles.Behavior;

            % Calculate frame
            myframe = ceil(handles.vlc.input.Time/1000 * handles.frameRate) - 1;

            handles.final_data.behavior(myframe) = behavior;

            display(handles.final_data(myframe, :))

            guidata(handles.hFigure, handles)
        end

 %% Not annotate, basic placeholder to not annotate   

    function NotAnnotate(varargin)    
        hFigure = findobj('tag', 'VideoPlay');
        handles = guidata(hFigure);
        % change value of the orther button to 0
        set(handles.hAnnotateButton, 'Value', 0);
    end


    function TogglePlayPause(varargin) 
        % Toggle Play/Pause 
        hFigure = findobj('tag', 'VideoPlay'); 
        handles = guidata(hFigure); 
        handles.vlc.playlist.togglePause(); 
    end

    function SeekToZero(varargin) 
        % Seek to begining of file 
        hFigure = findobj('tag', 'VideoPlay'); 
        handles = guidata(hFigure); 
        handles.vlc.input.Time = 0; 
    end

    function SeekToStartFrame(varargin) 
        % Seek StartFrame of file 
        hFigure = findobj('tag', 'VideoPlay'); 
        handles = guidata(hFigure); 
        handles.vlc.input.Time = StartFrame; 
    end

    function SeekToEndFrame(varargin) 
        % Seek to EndFrame of file 
        hFigure = findobj('tag', 'VideoPlay'); 
        handles = guidata(hFigure); 
        handles.vlc.input.Time = EndFrame;
     end

    function myRadio(RadioH, EventData)
        handles = guidata(RadioH);
        otherRadio = handles.radio(handles.radio ~= RadioH);
        set(otherRadio, 'Value', 0);
        set(handles.hAnnotateButton, 'Value', 0);
        handles.Behavior = RadioH.String;
        sprintf('Switching to...%s', handles.Behavior)
        guidata(handles.hFigure, handles)
    end 


% End of global function


    end

Did you try `guidata(hFigure, handles)`? Maybe the `hFigure` field of `handles` is being overwritten somewhere. Also, why do you have `varargin` in all your functions, if you don't use any input arguments? You can just say `function Annotate`. But better would be `function Annotate(hFigure)`, can pass the figure handle when you call it. That way you don't need to look for it all the time. — Cris Luengo, Apr 06 '18 at 03:54
@CrisLuengo `guidata(hFigure, handles)` produces the same result. I have `varargin` there becasue I'm going to pass more arguments as the thing grows, and it's a reminder to myself. True, I can pass `hFigure` but do you think the problem is related to not passing it? — Matias Andina, Apr 06 '18 at 13:46
I have no idea what the issue could be. If I were you I would set a breakpoint within this function and see what the value of `hFigure` is, see that it sets `guidata` properly, and see what else happens after this function was called. If you set a breakpoint (you can do this in the editor), your program will stop at that line. Then at the MATLAB command prompt you can execute commands as normal, but you'll be in your function's workspace, so you can examine and modify variables at will. And you can step through the program line by line. This is the best way of figuring out what happens. — Cris Luengo, Apr 06 '18 at 15:29
@CrisLuengo I will try the approach. It should be noted that the `display(...)` call prints the correct substitution to console. It must be the `guidata` not updating as expected — Matias Andina, Apr 06 '18 at 16:52
@CrisLuengo So I tried stopping at every guidata call in debug mode, objects on the workspace vary but handles does not appear in the workspace. The object is there because I can access data (which is correctly positioned in `handles.final_data`) — Matias Andina, Apr 06 '18 at 17:19
Don't rely on the workspace browser. Type `whos` to see the variables in the workspace. — Cris Luengo, Apr 06 '18 at 17:33
Have you tried with a simple `drawnow` command at the end of your Annotate function? This usually fixes these kinds of issues for me. — matiastofteby, Apr 09 '18 at 10:43
@matiastofteby `drawnow` does not change the mentioned behavior. — Matias Andina, Apr 09 '18 at 13:44

score 0 · Answer 1 · edited Oct 29 '20 at 17:59

This is a mix of updates and answers. I explored 2 options. First was leaving everything as is but running a global output data from the console before running the GUI and having things go there. The second approach is similar, but I unnested all the functions into separate .m files. Instead of a global, I have Annotate to call a assign('base', 'outputdata', outputdata). It is nasty and I don't fully like it, but it partially gets the job done. I welcome any suggestions to make it better.

score 0 · Answer 2 · answered Oct 20 '20 at 17:15

0

This is because the output variable is never updated with the new guidata...

Running your program with:

handles = AnnotateVideo(<filepath>)

You can update the structure handle with (from the commandline):

handles = guidata(handles.hFigure);

answered Oct 20 '20 at 17:15

Daniel Aldrich

328
3
10

score 0 · Answer 3 · edited Oct 30 '20 at 15:59

0

drawnow updates figures and processes any pending callbacks. Use this command if you modify graphics objects and want to see the updates on the screen immediately.

drawnow

edited Oct 30 '20 at 15:59

Enis Arik

665
10
24

answered Oct 29 '20 at 09:41

niko

100
4

guidata not updating in MATLAB GUI

3 Answers3